Other

• COPD exacerbations

  An acute worsening of respiratory symptoms that result in additional therapy
• Classifications of COPD exacerbations

  • Mild
  • Moderate
  • Severe
• Mild COPD exacerbation

  • Short acting bronchodilators (SABDs) only (e.g. inhaled salbutamol)
• Moderate COPD exacerbation

  • SABDs + antibiotics and/or oral corticosteroids
• Severe COPD exacerbation

  • Hospitalization or ER, may also be associated with acute respiratory failure
• Classification of hospitalized COPD exacerbation patients

  • No respiratory failure
  • Acute respiratory failure (non-life threatening)
  • Acute respiratory failure (life threatening)
• No respiratory failure

  • Respiratory rate: 20-30 breaths per minute
  • No use of accessory respiratory muscles
  • No changes in mental status
  • Hypoxemia improved with supplemental oxygen given via Venturi mask 28-35% inspired oxygen (FiO2)
  • No increase in PaCO2
• Acute respiratory failure (non-life threatening)

  • Respiratory rate: >30 breaths per minute
  • Using accessory respiratory muscles
  • No changes in mental status (not confused)
  • Hypoxemia improved with supplemental oxygen given via Venturi mask 25-30% inspired oxygen (FiO2)
  • Hypercarbia (i.e. PaCO2 increased compared with baseline or elevated 50-60 mmHg)
• Acute respiratory failure (life threatening)

  • Respiratory rate: >30 breaths per minute
  • Using accessory respiratory muscles
  • Acute changes in mental status (confused)
  • Hypoxemia not improved with supplemental oxygen given via Venturi mask or requiring >40% inspired oxygen (FiO2)
  • Hypercarbia (i.e. PaCO2 increased compared with baseline or elevated >60 mmHg) or presence of acidosis (pH≤7.25)
• Pharmacological management of COPD exacerbations

  1. Bronchodilators (inhaled or nebulizer, salbutamol and ipratropium bromide 4-6 hourly)

  2. Corticosteroids (OCS e.g. 30-40 mg Prednisolone for 5-7 days)

  3. Antibiotics (given if there's evidence of infection, cefaclor or co-amoxiclav if more purulent sputum or chest X-ray changes, modified based on sputum culture)
• Respiratory support for COPD exacerbations

  Noninvasive ventilation (NIV) - delivery of oxygen via a face or nasal mask, eliminating the need for endotracheal airway
• Indications for noninvasive mechanical ventilation (NIV)

  • Respiratory acidosis (PaCO2 ≥ 6.0 kPa or 45 mmHg and arterial PH ≤ 7.35)
  • Severe dyspnea with clinical signs suggestive of respiratory muscle fatigue, increased work of breathing or both
  • Persistent hypoxemia despite supplemental oxygen therapy
• Indications for respiratory or medical intensive care unit admission

  • Dyspnea: Severe dyspnea that responds inadequately to initial emergency therapy
  • Mental status: Confusion, lethargy and coma
  • Blood chemistry: Persistent/worsening hypoxemia (PaO2 < 5.3 kPa or 40 mmHg), severe/worsening respiratory acidosis (PH < 7.25) despite supplemental oxygen and noninvasive ventilation
  • Ventilation: need for invasive mechanical ventilation
  • Hemodynamic instability: need for vasopressors
• Why don't we give COPD patients as much oxygen as they need?